Voodoo, is a type of nature worship, where sacrifices and cannibalism intertwine. It is a type of dark magic that keeps high reverence for nature and it's wilds such as animals. While the practice can be dangerous, it is known to greatly benefit its practitioners. Trolls specifically, have always been followers of this ancient craft. Those trolls who practice the voodoo magics hold it to high regard and are a very important part of troll society. While it is a form of magic, it is only a extension of its masters, the Loa spirits. While the information is vague, Trolls worship the Loa gods which in turn grant them the use of voodoo. So it can be assumed that voodoo is more of a ceremonial practice for the trolls to honor their gods. However, Shadow hunters are voodoo warriors, so it can also be assumed that voodoo works as a tool to bless warriors and heal the sick. Whatever the case, Voodoo is used to honor Loa spirits which make this practice possible. To call Voodoo an evil magic, would be an overstatement. While its customs can be seen as evil, such as eating people, it is simply a tool to worship nature and its many spirits.

The exact emergence of this Magic on the planet of Azeroth, isn't known. However what is known of its origins is that the trolls have always practiced it which indicates its age, but the Loa spirits have always been connected to it. With the Loa gods being thousands of years if not predating Azeroth itself, It is safe to say that Voodoo is pretty old.

For centuries the trolls everywhere, Jungle to Ice, have been staunch worshipers of the Loa and use voodoo as a tool of worship. Such practices include human sacrifices and indulging in cannibalism. These practices haven't changed and are still used by every troll tribe even now.

While most trolls use voodoo to worship the Loa, lately the Darkspear Tribe have had some alterations to their practices. When Thrall and his Horde ran into the Darkspear Tribe in Stranglethorn Vale sailing to Kalimdor, The Orcs found broken people caused by the attacks of vicious Murlocs controlled by a Sea Witch. Their fate seemed sealed until the orcish Warchief Thrall and his band of newly freed orcs took shelter on their island home. Controlled by a Sea Witch, a group of rampaging murlocs captured the Darkspears' leader Sen'jin, along with Thrall and several other orcs and trolls. Thrall managed to free himself and others, but was ultimately unable to save the trolls' leader. Although Sen'jin was sacrificed to the Sea Witch, he was able to reveal a vision he had in which Thrall would lead the Darkspear Tribe from the island. After returning to the island, Thrall and his followers managed to fend off further attacks by the Sea Witch and her murloc minions, and set sail for Kalimdor once again. Under the new leadership of Vol'jin, the Darkspear swore allegiance to Thrall's Horde and followed him to Kalimdor.

The horde however looked down on the voodoo practices such as eating fallen enemies and sacrificing them to the gods. Thrall ordered Vol'Jin to tell his people to stop these practices that were shocking the Orcs. However the voodoo magics have long since been apart of the darkspear culture, and they weren't simply going to give it up. So in turn, they altered their practices. They kept the same gods and still used voodoo, but their human sacrifices would be changed to animal sacrifices. As for cannibalism, they had no option but to give it up all together. It is important to remember however, that this change in practice, only applies for the Darkspear tribe, as they joined the Horde.

Voodoo while used as a to benefit warriors or mages alike, is primarily a blessing from the gods used by trolls for worship. In troll society, a priest or shaman isn't so devoted to the Light or Elements as other races would be, instead, they tend to and worship the ancestors and spirits of their respected tribe or the land in general. They are known as witch doctors. Witch doctors hold an important position in troll society. Not only do Trolls respect their witch doctors as the wisest and most spiritual enlightened of the tribe, they are, as the name suggests, doctors and healers of the sick and wounded. They are shown courtesy and deference. Trolls are superstitious. They see bad omens everywhere and rely on witch doctors to interpret and exorcise these omens. Witch doctors govern success or failure in battle almost more than the warriors do; trolls believe that a witch doctor who reads the portents correctly and conducts the proper rituals can guarantee success in any endeavor. Until Thrall’s involvement with the Darkspear trolls, only male trolls became witch doctors. Female trolls have since seen the equality other Horde women possess and crave their own emancipation. Despite their efforts, few female witch doctors exist, and those who attempt to take on the role of tribal witch doctor meet with much derision and resistance. Trolls call female witch doctors “zufli,” a corruption of the voodoo master prefix “zul.” “Zufli” is a derogatory term and literally means “baby witch,” but some females have taken on the title as a mark of pride.

Some scholars view voodoo as a type of animism, and to an extent that theory is true. The trolls’ religion takes a decidedly different dark bent than the shamanistic beliefs of the orcs and tauren, though. Trolls have a complex belief system involving malign spirits and their effect on the world, but no scholar has established what is truth and what is simply long-held belief. The Darkspear trolls come from a dark and bloodthirsty history of sacrifice, cannibalism and black magic. They consider spirits to be individuals much like living creatures. Spirits are greedy, hostile and dangerous. Trolls also believe their ancestors linger on as jealous spirits who miss the land of the living and require blood sacrifices to appease them. Trolls sacrifice and eat their enemies. They conduct these practices for two reasons. First, they believe the sacrifice of sentient creatures appeases malicious spirits. Second, they believe that after death, an enemy’s spirit can visit misfortune on its killer. By consuming the flesh of their enemies, trolls believe they can also consume their enemy’s spirit, or at least damage it enough to render it impotent.

Troll death rituals used to involve ritual mutilation of the body. The trolls believed that simulating the sacrifice of a corpse distracted nearby malign spirits. The spirits, drawn to the pretend sacrifice, would fail to notice the new spirit entering their world. This allowed the deceased’s spirit to pass more easily into the next world and find a place for itself without harassment. Now trolls avoid these rituals because the Horde finds them disturbing and the rituals evoke unpleasant associations with the Scourge. Trolls frown on cremation, as they believe the body provides the spirit with a tie to the mortal world, and to destroy it sets a spirit adrift and confused for eternity. Recently the trolls have taken to cutting the eyes out of a corpse, thus opening a path into the skull where the spirit resides. Often a witch doctor sacrifices an animal nearby to distract any hungry spirits; if the mourners have no time for such a ritual, they may instead cut their arms and let their blood spill to achieve the necessary distraction. To avoid the possibility of undeath, trolls either bury their comrades’ bodies in hidden places or in sections (usually the body in one place and the head in another).

Each of the troll priests within Zul'Gurub worships a particular loa, called a primal god, and has the ability to assume an avatar of that god. For example, High Priest Venoxis can become the avatar of Hethiss (a snake).

There are four primal gods worshiped in Zul'Aman: the bear, lynx, dragonhawk, and eagle gods. In addition, any spirit of a dead ancestor — or even the Shadow ascendants of the Forsaken — can be considered loa.

Supposedly, upon his death, an enemy’s spirit lingers in his body for a short time. Then the spirit flees the corpse and is free to wreak havoc and revenge on its killer. Troll witch doctors believe that a fallen enemy’s spirit lairs in the corpse’s head before fleeing the body. Trolls who wish to trap enemy spirits often turn to head-shrinking. To shrink a head, a troll first decapitates his fallen
enemy. Then he makes a slit up the back of the head and carefully removes the skull (which he saves or discards). The troll then sews up the incision and boils the head for two hours to shrink. The troll uses scalding hot rocks and sand to fill the head cavity and shrink the head further. When the head is fist-sized and rubbery, the troll sews up the eyes, mouth, and neck with elaborate stitching. The enemy spirit now remains trapped inside the head forever. Most members of the Horde look askance at the practice of head-shrinking, but consider it a step up from human sacrifice and cannibalism. Some trolls have techniques to shrink skulls as well, which involve removing key pieces and reconstructing the skull as a smaller version using animal parts and resins to hold it together.[1](HPG 93)